The British prime minister sold his and wife Samantha’s shares in Blairmore Holdings — one of the tax haven schemes exposed in the Panama Papers leaks — in 2010 and insisted it was not set up as a tax dodge.
However, opposition politicians said he had given the clear impression he had something to hide by only revealing his involvement after days of pressure and a string of statements that failed to mention past investments.
They are pushing for Mr Cameron to come to the Commons on Monday to answer questions about the leak of millions of documents from Panama law firm Mossack Fonseca.
Mr Cameron said it was a “fundamental misconception” that Blairmore was set up to avoid paying UK tax and stressed that his interest in it had been “subject to all the UK taxes in the normal ways”.
He paid income tax on dividends but the £19,000 profit on the sale was insufficient to attract capital gains tax.
Mr Cameron also repeated his willingness to publish his tax return — and make it the norm for premiers and Opposition leaders.
“I want to be as clear as I can about the past, about the present, about the future, because, frankly, I don’t have anything to hide,” he said.
However, he also conceded that he was not able to “point to every source of every bit of the money” that his father left him when he died — around £300,000 — when asked whether it was linked to investments in Jersey.
Shadow chancellor John McDonnell declined to join calls for Mr Cameron to resign over the issue but said there had been an “erosion of trust” in Mr Cameron, who still had questions to answer.
They included why he intervened to stop EU plans to force trusts to face the same transparency as companies, he added.
Mr McDonnell said: “There’s significant erosion of trust in the prime minister because he wasn’t straight and he didn’t answer straight away and responses, as others have said, had to be dragged out of him.
“It’s not a matter of resignation at the moment, it’s a matter of making sure that the prime minister is straight with us.”
The shadow chancellor, who published his own tax affairs at the start of the year, said it was important for ministers to do the same.
He said: “I think it’s up to individual politicians but if you’re holding senior office, particularly in regards to the management of the economy, I think actually it’s important that you do — that’s why I published mine.”
Scottish first minister Nicola Sturgeon said that while Mr Cameron had previously “talked a good game on tax avoidance, we’ve found out this week the reality doesn’t always match the rhetoric”.